Characterization of various biochar feed stocks enriched with liquid fertilizers

Abstract

Biochar is a porous black carbon material produced through thermochemical reactions in lowoxygen conditions using agricultural and municipal waste materials. Methods such as slow pyrolysis, fast pyrolysis, and hydrothermal carbonization are used. Biochar offers substantial soil benefits, improving its physical, chemical, and biological characteristics. When enriched with liquid fertilizers, biochar becomes a nutrient-rich organic fertilizer solution. Hence the present study was executed with the aims of characterization of various biochar feedstocks enriched with liquid fertilizer. This experiment was conducted as a laboratory experiment at Fruit Crops Research and Development Institute, Kananwila, Horana, Sri Lanka to select the nutrient retention and exchange capacity with different biochar feedstocks. Rice husk, mushroom substrate, banana pseudo stem and coconut shell were used to make the four types of biochar. Ammonium Sulfate, monotassium phosphate, Potassium Chloride, Calcium Chloride, Magnesium Oxide and Zinc Sulfate Fertilizers were used to prepare liquid fertilizer solutions. Initially, 4 types of raw biochar were analyzed for their immediate, chemical, and nutritional elements. Proximate analysis was done as per ASTM D1762-84 method. Banana pseudo-stem biochar showed the best chemical and nutritional results. The nutrient absorbance capacity of each biochar has increased with the concentration of the liquid fertilizer. The nutrient absorbance results obtained from banana pseudo-stem and coconut shell biochar gave the best performances. Further, the study recommended to investigate the nutrient-releasing efficiency of these two biochar types before field applications.